Problem to be Solved
For many communications and radar applications a high power electromagnetic signal amplifier is required before transmission. At microwave frequencies the amplifier has traditionally been a traveling wave tube amplifier (TWTA). For various reasons such as reliability and biasing it is desirable to use a solid state power amplifier (SSPA) instead. To date, the SSPA's built using a single device have been limited to a few watts at Ku band, and fractions of a watt at K band and above. To get the desired tens or hundreds of watts it is necessary to combine the outputs of many individual amplifiers. The problem to be solved is how to do the power combining.